Here are the top 3 ways I answer the question, “What can I grow here?”
1: Existing Local Practices
In more developed areas there are lots of ways to know what people are already growing. Garden clubs, nurseries, seed-saver clubs, permaculture meet-up groups, etc, are all great ways to find out what’s growing in your area, and even to get some local seed that could be better adapted to your place. Especially in more developed areas of the world, where you can find organizations with a click o’ the internet, this is an easy and probably the most common way to find out what you can grow.
But what if you are somewhere you don’t have those associations, and where the internet gives you very little information? One method is to drive around neighborhoods or public buildings and look at the gardens they are growing. Especially at public buildings, these will often be maintained by immigrant workers, who tend to import practices and crops from back home if they are from a similar climate.
For me working in Saudi Arabia, I’ve visited some gardens run and maintained by Philipinos, who have brought moringa and sweet potato here. Initially I wouldn’t have thought to plant Moringa Oleifera here, because its native climate is more tropical and much more humid. However, i’ve observed some succesfully grown here, so I integrated them with my guild at work, in addition to the local Moringa Peregrina. Immigrants are a cultural edge and their introduction of exotic food plants can lead to innovative tries in your guild.
2: Local Historic Practices
Before industrialization, everybody except for a very few ate local. Traditional peoples and their food practices, whether currently existing or not, can point you in the direction of some plants that will be useful, and perhaps largely forgotten. Acorns, for example, were a staple of the pre-colonial peoples of New England, though I would venture to say that very few New Englanders consume them now. There are thousands of plants that can provide food, fiber, and medicine, that are almost entirely unknown to modern people, though in the past that was only sometimes the case.
3: A Climate Analogue
A climate analogue is a catalogue of other areas on the planet that share key characteristics that are similar or identical to the characteristics of the land you want to design for. Through a climate analogue, you can find nearly-identical climates across the globe, and then by researching plants in those areas, find all kinds of cool things you didn’t know you could grow. Here’s an example:
Take a look at the middle of the west coast of Saudi Arabia in the map above. It’s just inside the sub-tropics; now follow that latitude across the globe and note where it hits a western coast. Then do the same for the same latitude south of the equator (so if you’re looking at 20 North, you’ll want to look at 20 South as well because it’s the same solar pattern, just with the seasons flipped).
For my area in Saudi Arabia, following those latitudes, you hit the following areas: Coastal Namibia, Western Australia, A part of the Atacama in Chile, Mexicali, Mexico and the southern regions of the sonoran desert, Mauritania, A chunk of India, and Bangladesh. Those are the areas in my climate analogue. By researching traditional food plants from these areas, i can construct a guild of useful plants that are already growing somewhere with identical solar & in many instances climatic circumstances. In my own situation, every location on my climate analogue except for 2 are coastal deserts, just like the region I work in.
So that’s a very simplistic example. Here are the 6 characteristics you ought to look at when constructing a climate analogue:
C: Distance and direction from the nearest ocean, sea, or large body of water.
Those are the 3 most important. If you get a match on those 3, likelihood is that the next 3 will be comparable. These are:
D: Precipitation–if your analogue matches are the same on precipitation, then you know you can meet water sustainability by planting those imported plants.
E: dominant winds
F: major geographical features that would affect climate–mountains, rivers, seasonal storms, etc.
Bear in mind, none of the 6 characteristics above need to be identical, and you could eliminate the latter 3 altogether depending on the geography of your land. The more similar the matches you find in your climate analogue, the more succesful you will be implanting members of your guild from those areas.
If you are fortunate, after you build a climate analogue you will find 3 or 4 areas whose climates are very similar to yours. Then it is time for research. The same techniques you used in finding out already existing practices where you live, are the same you will use for these other areas that you have identified through your climate analogue.
Here are some plants i’ve adopted into my guild that I wouldn’t have thought to plant otherwise, or didn’t even know about when I started:
1: Moringa Oleifera can be found in Gujarat and Rajasthan, India, both of which match the climate analogue. This, combined with seeing it nearby in Jeddah led me to planting it out in our desert.
2: Pithecellobium dulce and honey mesquite (prosopis glandulosa). Both of these trees are native to Mexico, including the range on my climate analogue. The pith is pictured above.
3: Mongongo –this is the staple crop of the Bushmen in the Namib desert. I haven’t been able to plant it yet, but it should grow in Saudi Arabia because Namibia matches on all 6 of the above characteristics, and even has matching soil types.
4: Watermelon. Watermelon grows wonderfully in Saudi Arabia, and many people grow it here by flooding fields off of flash floods and sowing with watermelon seeds. Watermelon also happens to be native to Namibia.
5: Agaves (native to Mexico and the Sonoran Desert)
A Final Note on Natives vs. Non-natives
Just because you can grow something doesn’t mean you should. Know your goals for what you want to grow, consider the surrounding context and community, and bear in mind that people have moved plants all over the globe for a long, long time. It’s true that if we only ever grew natives, Italy would have no tomatoes, Ireland no potatoes, India no curry, Thailand no chiles, and the USA no wheat. However, that doesn’t mean you should throw caution to the wind, either.
A climate analogue can open up your eyes to lots of possibilities about what you can grow. If you combine that with a knowledge of local historical plant usage, you can come up with some wonderfully diverse guilding.